Instrument panel lighting assembly



May 20, 1958 J. M. ROPER INSTRUMENT PANEL LIGHTING ASSEMBLY Filed Sept.11, 1957 FIG. 4

FIG. 3

FIG; 2

JZJHN M- Ro'PER INVENTOR BY WATSOFLCOLE; Gamma WAT'SQN ATTORNEY United d:1

INSTRUMENT PANEL LIGHTING ASSEMBLY John M. Roper, Springfield, Md.Application September 11, 1957, Serial No. 683,300

6 Claims. (Cl. 240-316) This invention relates to panels which areilluminated so that the legends and indicia carried thereon may be readat night or under other circumstances involving the absence of adequatenatural lighting.

More particularly, this invention has reference to the illumination ofinstrument panels by light transmitted through the medium of thematerial of which the panel is composed. This light is usually suppliedby a source which is coupled closely to the panel and locatedsubstantially in the plane thereof. The rays of light are transmittededgewise of the body of the panel and confined therein except at theinformation areas defined by the legends or indicia.

In the usual practical installation of an illuminated panel of theforegoing type, the panel is fabricated from a plastic material which istransparent. The surfaces of the panel are processed with one or morecoatings of material which may,-for example, include a white vinyl layerapplied directly to the surfaces of the panel, and an overlying layer ofopaque black vinyl. The black vinyl layer is appropriately etched orengraved so as to expose portions of the white vinyl layer in accordancewith appropriate indicia or legends. The panel .thus fabricated isprocessed with one or more holes which individually receive anassociated lamp. These lamps when energized illuminate the interior ofthe panel, and inasmuch as the light is readily transmitted they alsoilluminate the legends which are rendered easily readable in contrast totheir opaque black background.

Various arrangements have heretofore been proposed in the prior art forparticular panel construction, including the application of variousoverlying layers of material for covering a transparent panel, and thepositioning and support of lamp sockets and the energizing conductorsfor these sockets upon the panel. In view of the considerable advancesmade within recent years in the instrumentation for aircraft and otherdevices requiring a panel type disposition of controls, considerabledemand now exists for commensurate improvements in the illuminated panelarrangements associated with such instrumentation.

Aircraft controls are becoming increasingly complex, resulting in arequirement for more switches, control dials, and terminal jacksprojecting or otherwise mounted at the control panel for access andmanipulation by the operator. Heretofore, the lamp arrangementsincorporated in the control panel for illuminating indicia or legendsassociated with the foregoing switches, dials and jacks in mostinstances have required that portions of the sockets for housing thesecomponents project from the front surface of the panel so that readyaccess may be had to the enclosed lamps. It may be readily appreciatedthat these socket projections interfered with the readability of thepanel instruments by increasing the number of components projecting fromthe front surfaces of the panel and presenting a highly complicatedarray to the operator. In many instances, the projecting (ill 2,835,789Patented May 20, 151758 2 lamp sockets obstructed the visibility ofmeter scales or the like.

Moreover, because of the constant supervisory demands made upon presentday aircraft pilots, close attention is not given in all instances tothe operation of the control panel switches. These switches are quitefrequently operated without directly viewing the control panel and onthe basis of experience. The presence of the projecting lamp socketsquite often result in the inadvertent twisting of socket caps in lieu ofthe proper switches or dials, thereby detracting from the pilotseffective control over the aircraft.

Accordingly, a principal object of this invention is to provide animproved lighting arrangement for instrumentation control panels whichis characterized by a complete absence of sockets or other lightingequipment from the front surface of the panel, thereby improving thevisibility of the controls and the readability of the informationlegends and, at the same time, substantially reducing the number ofcomponents prejecting from the front control panel surface which tend tocomplicate the appearance of the panel and confuse the operator.

Another object is to greatly simplify the construction of illuminatedcontrol panels so that they can be easily fabricated and installed.

Another object is to provide an illuminated control panel which willpromote the more effective sealing of the chassis box or the likecontaining the electrical and mechanical components which are undercontrol by the equipment operated from the panel.

Other objects will become apparent in. the ensuing specification andappended drawings in which:

Figure l is a perspective view showing an illuminated panel in positionfor placement in operative association with a central supporting panel;

Figure 2 is a view in section taken along the lines 2--2 of Figure 1;

Figure 3 is a view in elevation of the lamp support shown in Figure 2,and

Figure 4 is a view in section of a portion of the lamp support shown inFigure 2.

Referring now to the drawings, an indicia panel ll) has a pair of dialsl2 and 14 mounted thereon. A second panel 15 has mounted thereonsuitable shafts l6 and 18 to be connected to dials 12 and 14respectively. A pair of lamps are mounted in supporting sockets on panel1 3 and extend to the region of the front surface of panel lit, thesupports for the lamps being shown dotted at 2% and A pair ofprotruding, resiliently mounted plungers 5'7 and 58 are mounted on therear plate 15 to define electrical contacts for the lamps mounted insupports Eli and 22 respectively as will be subsequently explained.These lamps provide edgewise illumination of the translucent supportingpanel ltl and thus illuminate the indicia inscribed upon the forwardsurface of panel 19. These indicia may be marked on panel 10 in variousways well known in the art, one being to coat the entire surface blackexcept for the desired designations, so that light may penetratetherethro-ugh. A plurality of notches or apertures Fl? are provided inpanel ll) to permit the indicia panel to be mounted by means of mountingscrews on the front of an instrument case. A corresponding plurality ofapertures 32 are located in rear panel 15 to permit the mounting screwswhich hold the forward panel to also secure the rearward panel 15 inposition, the specific mounting arrangement being shown in greaterdetail in Figure 2.

Referring now to Figure 2, there is depicted, in section, a plasticmember Ml mounted in panel lit and having an aperture 34 which isadapted by its curvature to receive a lamp 36. The base 37 of lamp 36 issecured to a metallic cylindrical cap 39 by means of solder or otherequivalent means at point 41 adjacent the base of lamp 36.

Advantageously, a helical spring 40 is mounted on the base 37 of lamp 36and compressed between annular metallic ring 47 and plastic ring 43 toensure good electrical contact between ring 47 and base 37 of the lamp.This helical spring also serves to lock cylindrical member 39 intoposition when cylindrical member 39 is screwed down against the flangeof annular member 49.

A plastic annular ring 43 engages the base 37 of lamp 36 and alsoengages a shoulder 45 in cap 39 to insure adequate physical support forlamp 36. A pair of annular metallic rings 47 and 49 provide electricalconnections for the outer periphery of base 37 and the centrally locatedbase pin 42. Conductors 51 provide electrical connections betweenannular ring 49 and conductors such as 53 mounted in the forward panelin any convenient manner known in the art. Another pair of conductorssuch as conductor 55 are connected to annular ring 47 in a mannersimilar to the connection between conductor 51 and annular ring 49. Forexample, they m-ay be crimped between flanges of annular ring 49 andthereafter soldered, however, crimping alone may be sufficient toprovide adequate electrical contact. Since conductors 51 and 55 extendthrough plastic mem ber 20 at right angles, the connections betweenthese conductors and conductors 53 may be reversed to provide serialconnection between a pair of lamps by the rotation of base 20 through 90before base 20 is secured to panel 10.

Supporting panel has mounted therein a pair of resilient metallicplunger-s 57 one of which engages cap 39 in a region adjacent solderpoint 41 when the panels are mounted on an instrument case. Plunger 57is mounted in a cylindrical metallic member 59 and is biased by a pairof toroidal springs 61 and 63 which are separated by an annular guidemember 65. Cylindrical member 59 is secured in panel 15 by means offlange 67 engaging a recess in the forward surface of panel 15 and anannular Washer 68 and a nut 70 which threadably engages the outerperiphery of cylindrical member 59. A screw terminal 73 is mounted onthe rear of cylindrical member 59 and connected to plunger 57. A wireconnection such as wire 75 may be placed under the head of the screw ofterminal 73 and secured in position.

If, when the assembly is fabricated, one of the lamp supports, such assupport 20, is rotated 90 with respect to support 22, the two lamps willbe connected in parallel and plunger 57 may be connected to' ground orreference potential while plunger 58 may be connected to a source ofelectromotive force, such as a battery. With such an arrangement,plungers 57 and 58 define the only electrical connections to the frontpanel 10 and facilitate removal of the front panel for maintenance andreplacement of the lamps.

Another combination of flush-mounted lamp support and indicia panel isdisclosed and described in my application Serial No. 609,289, filedSeptember 11, 1956.

While one preferred embodiment of this invention has been specificallydisclosed it is understood that the invention is not limited thereto asmany variations will be readily apparent to those skilled in the art andthe invention is to be given its broadest possible interpretation withinthe terms of the following claims.

For example the resilient pins 57 and 58 may be mounted within thecontrol box (not shown).

I claim:

1. The combination of a translucent panel having a translucent lampsupporting member secured thereto substantially flush with the forwardsurface of said panel, a cap member for said supporting member andhaving a lamp therein, said lamp being secured to said cap memher, afirst annular metallic ring mounted on the outer periphery of said lampsupport, a second annular metallic ring mounted on the inner peripheryof said lamp support, conductors connected to each of said annularmetallic rings, a plastic annular ring encircling said lamp and securedto said cap member, a helical spring surrounding the base of said lampand engaging one of said annular metallic rings and said annular plasticring, conductor means connected to said conductors and resilientlymounted pin means for defining an electrical contact with the said capmember.

2. The combination as claimed in claim 1 wherein said resilient pinmeans includes a metallic pin mounted in a second panel and including apair of helical springs having a guiding device mounted therebetween.

3. The combination as claimed in claim 1 wherein said conductors extendthrough said lamp supporting member at substantially right angles toeach other whereby the connections between said conductcrs and saidconductor means may be reversed by rotating said lamp supporting member.

4. The combination of a translucent panel having a translucent lampsupporting member secured thereto substantially flush with the forwardsurface of said panel, a cap member having a lamp secured therein, afirst annular metallic ring mounted on the outer periphery of said lampsupporting member, said cap engaging said first annular metallic ring, asecond annular metallic ring mounted on the inner periphery of said lampsupport for contacting the base of said lamp, conductors connected toeach of said annular metallic rings, conducting means connected to saidconductors and a second panel having a resilient metallic pin mountedtherein for engaging said cap member to define an electrical connectiontherewith.

5. The combination as claimed in claim 4 further comprising helicalspring means surrounding the base of said lamp and engaging said secondannular metallic ring.

6. The combination as claimed in claim 4 wherein said conductors extendradially through said lamp supporting member in difierent directions inthe same transverse plane and wherein said conducting means includes aplurality of conductors lying in the same transverse plane whereby theconnections between said contors and said conducting means may bereversed by rotating said lamp supporting member.

References Cited in the file of this patent UNITED STATES PATENTS2,087,935 Batcheller July 27, 1937 2,242,165 Batcheller May 13, 19412,681,980 Harrington June 22, 1954 2,695,354 Nevgass Nov. 23, 1954

